<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>选择器</title>
    <style>

        div{
            color: red;
        }
        .cls{
            color: blue;
        }
        #d1{
            color:deeppink;
        }
        #d1{
            color:brown;
        }
    </style>
</head>
<body>
    <div class="cls" id="d1">div</div>
</body>
</html>